The invention relates to novel sulphur products compatible with lubricating oils. It also relates to the preparation of these products and their use as additives having an extreme pressure and antiwear actions in mineral or synthetic, lubricating oils, e.g. in engine oils, gear oils, hydraulic fluids or metal working oils.
Superbasic detergent additives have been known for a long time. Certain of them and their preparation have e.g. been described in U.S. Pat. Nos. 2,865,956, 3,150,088, 3,537,996, 3,830,739, 3,865,737, 4,148,740, 3,953,519, 3,966,621 and 4,505,830 and French Patent 2,101,813. There are variants of the superbasification reaction using high performance carbonates based on alkoxides and CO.sub.2, prior to the contacting with the alkali metal or alkaline earth salt of the acid compound and are more particularly described in U.S. Pat. Nos. 2,956,018, 3,932,289 and 4,104,180.
It is also known to modify superbasic detergent additives by incorporating boron derivatives, as is e.g. described in U.S. Pat. Nos. 3,929,650, 3,907,691, 4,965,003 and 4,965,004.
Finally, the modification of superbasic detergent additives by certain carboxylic acids, boric acids or phosphoric acids has also been described in U.S. Pat. No. 4,328,111.